You can preorder it and pick it up in-store day of release, which is what I plan to do. The preorder just ensures that you will have a copy to pick up when you get there.
You can't do that, though, if the company incompetently sells your preordered copy away by mistake, which has happened to me before. They had one shipped in from another store. Frankly, I was not satisfied. I think I should have gotten free two day shipping and a discount after waiting for an hour and a half only to tell me I have to waste more gas to come back in three days...